1. Field of the Invention
The present invention relates to a proportional valve and, more particularly, to an electrically controlled proportional valve having a movable valve element which is in the form of an orbital leaf spring valve element, and which also comprises the armature operated by the electromagnet coil.
2. Description of the Related Art
Proportional valves are useful in pneumatic control circuits, and may be used, for example, to control precise gas flow through the valve. A search of the prior art did not disclose any patents that read directly on the claims of the instant invention; however, of considerable relevance is U.S. Pat. No. 6,220,569 to Kelly which shows an electrically operated pneumatic valve in which a combination magnetically operated armature and an angled surface of the valve case are biased so as to proportionally control flow. However, in such a configuration the total travel distance of the moment arm, and therefore the resultant flow resolution and armature stability, is limited by the total radial distance of the armature, as opposed to the proposed orbital leaf spring design.
This limitation is overcome by the present invention. The proposed orbital leaf spring increases the available travel distance of the moment arm by a minimum of three fold, due to its orbital positioning and structure, thereby increasing performance resolution and armature stability.
Consequently, a need has been felt for providing an electrically operated pneumatic valve utilizing an orbital leaf spring.